Securities (Restricted Stock) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Securities [Line Items]
Restricted stock, at amortized cost	$ 16,572	$ 10,092
Restricted Stock [Member] | Federal Reserve Bank Stock [Member]
Securities [Line Items]
Restricted stock, at amortized cost	8,407	999
Restricted Stock [Member] | Federal Home Loan Bank Certificates and Obligations (FHLB) [Member]
Securities [Line Items]
Restricted stock, at amortized cost	$ 8,165	$ 9,093